Even if we assume battery size/shape standardization, this would move the baterry liability from the car owner to the battery pack vendor, since they would have

Even if we assume battery size/shape standardization, this would move the baterry liability from the car owner to the battery pack vendor, since they would have to maintain the batteries in circulation (introduce new ones, retire old ones) etc. This would require crazy high locked capital and it would cause the cost to be prohibitively high for a casual weekly swap.